VMware is the latest company to throw its heft behind OpenStack, the cloud operating system that kicked off two-and-a-half years ago to enable any organization to offer open source software and services. Contributors to the OpenStack project include IBM, Rackspace, and Amazon.

Canonical’s Ubuntu, one of the most popular OpenStack distributions, will now include the plug-ins necessary to operate with VMware technologies, including vSphere or Vicira NVP. Canonical is a 600-person company that competes with Microsoft on desktop, Citrix, and VMware. “In every part of our history, we are encroaching on other people’s territory — but at the same time, we collaborate on OpenStack,” said Mark Baker, a product manager at Canonical, in a recent interview.

This is a major announcement for the industry — and somewhat of a surprise — as VMware hasn’t always embraced the project. Mirantis CEO Boris Renski wrote in a blog post that VMware is a competitor to OpenStack and should take part in the initiative.

Kyle MacDonald, Canonical’s cloud vice president, said in a recent interview that this is an “astute move” for VMware. “They are taking their enterprise business and partnering it with an open source project to try to get the best of both worlds,” he continued.

McDonald, who has defended VMware in the past, said that customers can now “reuse VMware estate with an open-source stack.” It’s a far cry from a world where “you’re either VMware or you’re not.”